1. Field of the Invention
The present invention relates to a traction control system capable of preventing an automobile from the acceleration slip by means of controlling the engine throttle.
2. Description of the Related Art
Hitherto, there has been a traction control system for a vehicle disclosed in US 4, 722, 411 of a type arranged such that the engine throttle is controlled.
The vehicle traction control system of the type disclosed as described above is arranged in such a manner that: a main throttle valve to be operated by an accelerator pedal and a sub-throttle valve to be controlled by an electronic control circuit are connected to a suction pipe in series; the sub-throttle valve is closed in response to a signal supplied from the electronic control circuit when the driving wheel encounters an acceleration slip so that the output is lowered by restricting the amount of air intake into the engine and the driving force of the driving wheel is reduced.
However, in the above-described type traction control system for a vehicle by means of controlling the engine throttle, the size of the portion of the engine including the suction pipe becomes too large since two throttle valves, that is, the main throttle valve and the subthrottle valve, needs to be provided for the suction pipe.